Experimental Research And Optimization Of Radiant Cooling Air Conditioning System

With the development and progress of society,the energy consumption of buildings in China is increasing year by year.At the same time,people’s demand for indoor thermal comfort is higher and higher,so the energy consumption of air conditioning system is also significantly improved.Radiant cooling air-conditioning system,as a new cooling mode with vigorous development,has attracted widely attention,with the characteristics of energy saving and good comfort.In this paper,a series of experiments and simulation studies are carried out on the radiation cooling combined with independent fresh air conditioning system of a building in Shanghai.Firstly,the air-conditioning system is tested in the cooling season.The indoor temperature and relative humidity are measured,and the energy consumption of the air-conditioning system in the whole cooling season is calculated.The results show that the air-conditioning system can meet the needs of indoor thermal comfort.Then,the model is established by using Airpak software,and the influence of the radiation terminal position on the indoor thermal environment is analyzed.The temperature of the radiation plate is explored to achieve the best indoor thermal comfort.When the radiation terminal surface temperature is 21～22℃,the PPD value is less than 6%.In addition,the indoor air distribution under different air supply modes of the fresh air system is compared.The results show that the bottom vertical air supply is the best way of fresh air supply.Furthermore,Trnsys software is used to simulate the operation of the whole air-conditioning system.Based on the actual cooling load characteristics of the building,the operation schedule of the air conditioning system is optimized,and the energy consumption of the system is reduced by 20.6%.Then the variable water flow control strategy is designed,and the indoor temperature compliance rate is increased to96.9%,.Finally,the mathematical model of the pipe network system is established by using the graph theory,and the correlation of the hydraulic loss of the radiation end of the capillary network with the change of the pipe length,water flow and the number of pipes is obtained by fitting.The real-time control algorithm of building air conditioning water system based on graph theory is designed to ensure the implementation of the variable water flow control strategy.